Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Many physical activities require a participant in the activity to perform to the limit of their physical ability, testing the participant's endurance, strength, coordination, shock tolerance, or other physical variables. Warfighters can be expected to carry heavy loads across long distances, taxing their endurance and risking injury due to falls, unstable terrain, or other unanticipated physical shocks. The elderly or the physically disabled can experience difficulty in performing activities of daily living, due to reduced endurance, strength, injury-resistance, balance, or other issues. Movers or other persons engaged in physical labor can be at increased risk of injury due to repeatedly lifting heavy loads over long durations and difficulty coordinating physical efforts (e.g., lifting a large object) between multiple people. Athletes can be exposed to joint, tendon, or other forces sufficient to cause significant temporary or permanent injury. Individuals recovering from surgery or a disabling injury may be unable to perform the minimum tasks necessary to begin rehabilitation, and thus may be barred from recovery. Other examples exist of populations and activities that respectively may require more physical ability than is available to members of the population or to participants in the activities.
Assistive devices may be able to alleviate some of these issues. A variety of assistive devices, including various exoskeleton-based devices, have been developed to increase a user's strength, fatigue resistance, coordination, or other factors. These exoskeletons or other devices can be powered or unpowered, and may be controlled by feedback from the user's movements, be operated in a feed-forward manner, or be completely passive (e.g., hernia belts, lifting harnesses). Assistive devices can include electrical or mechanical actuators, sensors, and controllers. Various assistive devices have been applied to some of the above populations and activities with varying degrees of success.